Branched polydiorganosiloxane polyamide copolymers

ABSTRACT

Branched polydiorganosiloxane polyamide, block copolymers and methods of making the copolymers are provided. The method of making the copolymers involves reacting one or more amine compounds including at least one polyamine with a precursor having at least one polydiorganosiloxane segment and at least two ester groups.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 12/717,226, filedMar. 4, 2010, now issued as U.S. Pat. No. 7,915,370, which is adivisional of U.S. Ser. No. 11/821,572, filed Jun. 22, 2007, now issuedas U.S. Pat. No. 7,705,101, the disclosure of which is incorporated byreference in its entirety herein.

TECHNICAL FIELD

Branched polydiorganosiloxane polyamide copolymers and methods of makingthe copolymers are described.

BACKGROUND

Siloxane polymers have unique properties derived mainly from thephysical and chemical characteristics of the siloxane bond. Theseproperties include low glass transition temperature, thermal andoxidative stability, resistance to ultraviolet radiation, low surfaceenergy and hydrophobicity, high permeability to many gases, andbiocompatibility. The siloxane polymers, however, often lack tensilestrength.

The low tensile strength of the siloxane polymers can be improved byforming block copolymers. Some block copolymers contain a “soft”siloxane polymeric block or segment and any of a variety of “hard”blocks or segments. Polydiorganosiloxane polyamides andpolydiorganosiloxane polyureas are exemplary block copolymers.

Polydiorganosiloxane polyamides have been prepared by condensationreactions of amino terminated silicones with short-chained dicarboxylicacids. Alternatively, these copolymers have been prepared bycondensation reactions of carboxy terminated silicones withshort-chained diamines. Because polydiorganosiloxanes (e.g.,polydimethylsiloxanes) and polyamides often have significantly differentsolubility parameters, it can be difficult to find reaction conditionsfor production of siloxane-based polyamides that result in high degreesof polymerization, particularly with larger homologs of thepolyorganosiloxane segments. Many of the known siloxane-based polyamidecopolymers contain relatively short segments of the polydiorganosiloxane(e.g., polydimethylsiloxane) such as segments having no greater than 30diorganosiloxy (e.g., dimethylsiloxy) units or the amount of thepolydiorganosiloxane segment in the copolymer is relatively low. Thatis, the fraction (i.e., amount based on weight) of polydiorganosiloxane(e.g., polydimethylsiloxane) soft segments in the resulting copolymerstends to be low.

Polydiorganosiloxane polyureas are another type of block copolymer.Although these block copolymers have many desirable characteristics,some of them tend to degrade when subjected to elevated temperaturessuch as 250° C. or higher.

SUMMARY

In one aspect, the present disclosure provides a copolymer including atleast two repeat units of Formula I (I-a and/or I-b):

each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, oraryl substituted with an alkyl, alkoxy, or halo; G is a polyvalentresidue having a valence of q; R³ is hydrogen or alkyl or R³ takentogether with G and to the nitrogen to which they are both attached forma heterocyclic group; each Y is independently an alkylene, aralkylene,or a combination thereof; each B is independently a covalent bond (e.g.,a repeat unit of Formula I-b), an alkylene of 4-20 carbons, anaralkylene, an arylene, or a combination thereof; n is independently aninteger of 0 to 1500; p is an integer of 1 to 10; and q is an integergreater than 2. Compositions and articles (e.g., films and/or compositefilms) including one or more copolymers having at least two repeat unitsof Formula I (I-a and/or I-b) are also disclosed herein. The branchedcopolymer can additionally include different repeat units such as, forexample, repeat units of Formula I, but wherein q is equal to 2.

In another aspect, the present disclosure provides a method of making acopolymer of Formula I (I-a and/or I-b). The method includes mixingtogether under reaction conditions: a) a precursor of Formula II-a:

and b) one or more amine compounds having on average a formulaG(NHR³)_(r), wherein: each R¹ is independently an alkyl, haloalkyl,aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, orhalo; each R² is independently an alkyl, haloalkyl, aryl, or arylsubstituted with an alkyl, alkoxy, halo, or alkoxycarbonyl; G is apolyvalent residue unit equal to the formula G(NHR³)_(r) minus the r—NHR³ groups; R³ is hydrogen or alkyl or R³ taken together with G andwith the nitrogen to which they are both attached forms a heterocyclicgroup; and each Y is independently an alkylene, aralkylene, or acombination thereof; each B is independently a covalent bond (e.g., aprecursor of Formula II-b), an alkylene of 4-20 carbons, an aralkylene,an arylene, or a combination thereof; and n is independently an integerof 0 to 1500; p is an integer of 1 to 10; and r is a number greater than2. The branched copolymer can additionally include different repeatunits such as, for example, repeat units of Formula I, but wherein q isequal to 2.

In certain embodiments, the present disclosure provides a process forproducing a mixture, wherein the process includes: continuouslyproviding at least one branched polydiorganosiloxanepolyamide-containing component and at least one organic polymer to avessel; mixing the components to form a mixture; and conveying themixture from the vessel.

In certain embodiments, the mixing is under substantially solventlessconditions.

In certain embodiments, the present disclosure provides a process forproducing a mixture, wherein the process includes: continuouslyproviding reactant components for making at least one branchedpolydiroganosiloxane polyamide and at least one organic polymer that isnot reactive with the reactant components; mixing the components;allowing the reactant components to react to form a branchedpolydiorganosiloxane amide segmented copolymer, and conveying themixture from the reactor.

Branched polydiorganosiloxane polyamide copolymers can exhibit acombination of high viscosity and thermal stability at elevatedtemperatures (e.g., 200° C. to 300° C.). The high viscosity can beuseful, for example, for control of rheology at elevated temperaturesthat can be encountered during processing of the polymers inapplications such as coextrusion of multilayer films.

Branched polydiorganosiloxane polyamide copolymers can be conceived foruse in numerous applications including, for example, in sealants,adhesives, as material for fibers, as plastics additives, e.g., asimpact modifiers or flame retardants, as material for defoamerformulations, as a high-performance polymer (thermoplastic,thermoplastic elastomer, elastomer), as packaging material forelectronic components, in insulating materials or shielding materials,in cable sheathing, in antifouling materials, as an additive forscouring, cleaning, or polishing products, as an additive for bodycarecompositions, as a coating material for wood, paper, and board, as amold release agent, as a biocompatible material in medical applicationssuch as contact lenses, as a coating material for textile fibers ortextile fabric, as a coating material for natural substances such asleather and furs, for example, as a material for membranes and as amaterial for photoactive systems, for example, for lithographictechniques, optical data securement or optical data transmission.

DEFINITIONS

The terms “comprises” and variations thereof do not have a limitingmeaning where these terms appear in the description and claims.

The words “preferred” and “preferably” refer to embodiments of theinvention that may afford certain benefits, under certain circumstances.However, other embodiments may also be preferred, under the same orother circumstances. Furthermore, the recitation of one or morepreferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the invention.

The terms “a”, “an”, and “the” are used interchangeably with “at leastone” to mean one or more of the elements being described.

As used herein, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The term “and/or” means one or all of the listed elements or acombination of any two or more of the listed elements.

The term “alkenyl” refers to a monovalent group that is a radical of analkene, which is a hydrocarbon with at least one carbon-carbon doublebond. The alkenyl can be linear, branched, cyclic, or combinationsthereof and typically contains 2 to 20 carbon atoms. In someembodiments, the alkenyl contains 2 to 18, 2 to 12, 2 to 10, 4 to 10, 4to 8, 2 to 8, 2 to 6, or 2 to 4 carbon atoms. Exemplary alkenyl groupsinclude ethenyl, n-propenyl, and n-butenyl.

The term “alkyl” refers to a monovalent group that is a radical of analkane, which is a saturated hydrocarbon. The alkyl can be linear,branched, cyclic, or combinations thereof and typically has 1 to 20carbon atoms. In some embodiments, the alkyl group contains 1 to 18, 1to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples ofalkyl groups include, but are not limited to, methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl,n-heptyl, n-octyl, and ethylhexyl.

The term “alkylene” refers to a divalent group that is a radical of analkane. The alkylene can be straight-chained, branched, cyclic, orcombinations thereof. The alkylene often has 1 to 20 carbon atoms. Insome embodiments, the alkylene contains 1 to 18, 1 to 12, 1 to 10, 1 to8, 1 to 6, or 1 to 4 carbon atoms. The radical centers of the alkylenecan be on the same carbon atom (i.e., an alkylidene) or on differentcarbon atoms.

The term “alkoxy” refers to a monovalent group of formula —OR where R isan alkyl group.

The term “alkoxycarbonyl” refers to a monovalent group of formula—(CO)OR where R is an alkyl group and (CO) denotes a carbonyl group withthe carbon attached to the oxygen with a double bond.

The term “aralkyl” refers to a monovalent group of formula —R^(a)—Arwhere R^(a) is an alkylene and Ar is an aryl group. That is, the aralkylis an alkyl substituted with an aryl.

The term “aralkylene” refers to a divalent group of formula—R^(a)—Ar^(a)— where R^(a) is an alkylene and Ar^(a) is an arylene(i.e., an alkylene is bonded to an arylene).

The term “aryl” refers to a monovalent group that is aromatic andcarbocyclic. The aryl can have one to five rings that are connected toor fused to the aromatic ring. The other ring structures can bearomatic, non-aromatic, or combinations thereof. Examples of aryl groupsinclude, but are not limited to, phenyl, biphenyl, terphenyl, anthryl,naphthyl, acenaphthyl, anthraquinonyl, phenanthryl, anthracenyl,pyrenyl, perylenyl, and fluorenyl.

The term “arylene” refers to a divalent group that is carbocyclic andaromatic. The group has one to five rings that are connected, fused, orcombinations thereof. The other rings can be aromatic, non-aromatic, orcombinations thereof. In some embodiments, the arylene group has up to 5rings, up to 4 rings, up to 3 rings, up to 2 rings, or one aromaticring. For example, the arylene group can be phenylene.

The term “aryloxy” refers to a monovalent group of formula —OAr where Aris an aryl group.

The term “carbonyl” refers to a divalent group of formula —(CO)— wherethe carbon atom is attached to the oxygen atom with a double bond.

The term “halo” refers to fluoro, chloro, bromo, or iodo.

The term “haloalkyl” refers to an alkyl having at least one hydrogenatom replaced with a halo. Some haloalkyl groups are fluoroalkyl groups,chloroalkyl groups, or bromoalkyl groups.

The term “heteroalkylene” refers to a divalent group that includes atleast two alkylene groups connected by a thio, oxy, or —NR— where R isalkyl. The heteroalkylene can be linear, branched, cyclic, orcombinations thereof and can include up to 60 carbon atoms and up to 15heteroatoms. In some embodiments, the heteroalkylene includes up to 50carbon atoms, up to 40 carbon atoms, up to 30 carbon atoms, up to 20carbon atoms, or up to 10 carbon atoms. Some heteroalkylenes arepolyalkylene oxides where the heteroatom is oxygen.

The term “oxalyl” refers to a divalent group of formula —(CO)—(CO)—where each (CO) denotes a carbonyl group.

The terms “oxalylamino” and “aminoxalyl” are used interchangeably torefer to a divalent group of formula —(CO)—(CO)—NH— where each (CO)denotes a carbonyl.

The term “aminoxalylamino” refers to a divalent group of formula—NH—(CO)—(CO)—NR^(d)— where each (CO) denotes a carbonyl group and R^(d)is hydrogen, alkyl, or part of a heterocyclic group along with thenitrogen to which they are both attached. In most embodiments, R^(d) ishydrogen or alkyl. In many embodiments, R^(d) is hydrogen.

The term “polyvalent” refers to a group having a valence of greater than2.

The terms “polymer” and “polymeric material” refer to both materialsprepared from one monomer such as a homopolymer or to materials preparedfrom two or more monomers such as a copolymer, terpolymer, or the like.Likewise, the term “polymerize” refers to the process of making apolymeric material that can be a homopolymer, copolymer, terpolymer, orthe like. The terms “copolymer” and “copolymeric material” refer to apolymeric material prepared from at least two monomers.

The term “polydiorganosiloxane” refers to a divalent segment of formula

where each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl,aryl, or aryl substituted with an alkyl, alkoxy, or halo; each Y isindependently an alkylene, aralkylene, or a combination thereof; andsubscript n is independently an integer of 0 to 1500.

The terms “room temperature” and “ambient temperature” are usedinterchangeably to mean temperatures in the range of 20° C. to 25° C.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about.” Accordingly, unless indicated to the contrary, the numbers setforth are approximations that can vary depending upon the desiredproperties using the teachings disclosed herein.

The above summary of the present invention is not intended to describeeach disclosed embodiment or every implementation of the presentinvention. The description that follows more particularly exemplifiesillustrative embodiments. In several places throughout the application,guidance is provided through lists of examples, which can be used invarious combinations. In each instance, the recited list serves only asa representative group and should not be interpreted as an exclusivelist.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Branched polydiorganosiloxane polyamide block copolymers and methods ofmaking the copolymers are provided. The branched polydiorganosiloxanepolyamide copolymers are the condensation reaction product of (a) one ormore amine compounds including at least one polyamine, the one or moreamine compounds having primary or secondary amino groups with (b) aprecursor having at least one polydiorganosiloxane segment and at leasttwo ester groups. As used herein, the term “branched” is used to referto a polymer chain having branch points that connect three or more chainsegments. Examples of branched polymers include long chains havingoccasional and usually short branches including the same repeat units asthe main chain (nominally termed a branched polymer). The branchedpolydiorganosiloxane polyamide block copolymers can optionally formcross-linked networks.

In certain embodiments, the block copolymers are branchedpolydiorganosiloxane polyoxamide block copolymers. Such branchedpolydiorganosiloxane polyoxamide copolymers are the condensationreaction product of (a) one or more amine compounds including at leastone polyamine, the one or more amine compounds having primary orsecondary amino groups with (b) a precursor having at least onepolydiorganosiloxane segment and at least two oxalylamino groups.

The branched copolymers can have many of the desirable features ofpolysiloxanes such as low glass transition temperatures, thermal andoxidative stability, resistance to ultraviolet radiation, low surfaceenergy and hydrophobicity, and high permeability to many gases.Additionally, the branched copolymers can have improved mechanicalstrength and elastomeric properties compared to polysiloxanes and linearpolydiorganosiloxane polyamide block copolymers. At least some of thebranched copolymers are optically clear, have a low refractive index, orboth.

Polydiorganosiloxane Polyamide Block Copolymers

A branched, polydiorganosiloxane polyamide block copolymer is providedthat contains at least two repeat units of Formula I-a.

In this formula, each R¹ is independently an alkyl, haloalkyl, aralkyl,alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo. EachY is independently an alkylene, aralkylene, or a combination thereof.Subscript n is independently an integer of 0 to 1500 and the subscript pis an integer of 1 to 10. Group G is a polyvalent residue having avalence of q, wherein q is an integer greater than 2. In certainembodiments q can, for example, be equal to 3 or 4. Group R³ is hydrogenor alkyl (e.g., an alkyl having 1 to 10, 1 to 6, or 1 to 4 carbon atoms)or R³ taken together with G and with the nitrogen to which they are bothattached forms a heterocyclic group (e.g., R³HN-G-NHR³ is piperazine orthe like). Each B is independently a covalent bond, an alkylene of 4-20carbons, an aralkylene, an arylene, or a combination thereof. When eachgroup B is a covalent bond, the branched, polydiorganosiloxane polyamideblock copolymer having repeat units of Formula I-a is referred to as abranched, polydiorganosiloxane polyoxamide block copolymer, andpreferably has repeat units of Formula I-b shown below. Each asterisk(*) indicates a site of attachment of the repeat unit to another groupin the copolymer such as, for example, another repeat unit of Formula I(I-a or I-b). The branched copolymer can additionally include differentrepeat units such as, for example, repeat units of Formula I, butwherein q is equal to 2.

A preferred branched, polydiorganosiloxane polyoxamide block copolymercontains at least two repeat units of Formula I-b.

In this formula, each R¹ is independently an alkyl, haloalkyl, aralkyl,alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo. EachY is independently an alkylene, aralkylene, or a combination thereof.Subscript n is independently an integer of 0 to 1500 and the subscript pis an integer of 1 to 10. Group G is a polyvalent residue having avalence of q, wherein q is an integer greater than 2. In certainembodiments q can be, for example, equal to 3 or 4. Group R³ is hydrogenor alkyl (e.g., an alkyl having 1 to 10, 1 to 6, or 1 to 4 carbon atoms)or R³ taken together with G and with the nitrogen to which they are bothattached forms a heterocyclic group (e.g., R³HN-G-NHR³ is piperazine orthe like). Each asterisk (*) indicates a site of attachment of therepeat unit to another group in the copolymer such as, for example,another repeat unit of Formula I (I-a or I-b).

Suitable alkyl groups for R¹ in Formula I (I-a or I-b) typically have 1to 10, 1 to 6, or 1 to 4 carbon atoms. Exemplary alkyl groups include,but are not limited to, methyl, ethyl, isopropyl, n-propyl, n-butyl, andiso-butyl. Suitable haloalkyl groups for R¹ often have only a portion ofthe hydrogen atoms of the corresponding alkyl group replaced with ahalogen. Exemplary haloalkyl groups include chloroalkyl and fluoroalkylgroups with 1 to 3 halo atoms and 3 to 10 carbon atoms. Suitable alkenylgroups for R¹ often have 2 to 10 carbon atoms. Exemplary alkenyl groupsoften have 2 to 8, 2 to 6, or 2 to 4 carbon atoms such as ethenyl,n-propenyl, and n-butenyl. Suitable aryl groups for R¹ often have 6 to12 carbon atoms. Phenyl is an exemplary aryl group. The aryl group canbe unsubstituted or substituted with an alkyl (e.g., an alkyl having 1to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms), analkoxy (e.g., an alkoxy having 1 to 10 carbon atoms, 1 to 6 carbonatoms, or 1 to 4 carbon atoms), or halo (e.g., chloro, bromo, orfluoro). Suitable aralkyl groups for R¹ usually have an alkylene groupwith 1 to 10 carbon atoms and an aryl group with 6 to 12 carbon atoms.In some exemplary aralkyl groups, the aryl group is phenyl and thealkylene group has 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4carbon atoms (i.e., the structure of the aralkyl is alkylene-phenylwhere an alkylene is bonded to a phenyl group).

In some repeat units of Formula I (I-a or I-b), all R¹ groups can be oneof alkyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with analkyl, alkoxy, or halo (e.g., all R¹ Groups are an alkyl such as methylor an aryl such as phenyl). In some compounds of Formula II, the R¹groups are mixtures of two or more selected from the group consisting ofalkyl, haloalkyl, aralkyl, alkenyl, aryl, and aryl substituted with analkyl, alkoxy, or halo in any ratio. Thus, for example, in certaincompounds of Formula I, 0%, 1%, 2, %, 5%, 10%, 20%, 30%, 40%, 50%, 60%,70%, 80%, 90%, 95%, 98%, 99%, or 100% of the R¹ groups can be methyl;and 100%, 99%, 98%, 95%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%,5%, 2%, 1%, or 0% of the R¹ groups can be phenyl.

In some repeat units of Formula I (I-a or I-b), at least 50 percent ofthe R¹ groups are methyl. For example, at least 60 percent, at least 70percent, at least 80 percent, at least 90 percent, at least 95 percent,at least 98 percent, or at least 99 percent of the R¹ groups can bemethyl. The remaining R¹ groups can be selected from an alkyl having atleast two carbon atoms, haloalkyl, aralkyl, alkenyl, aryl, or arylsubstituted with an alkyl, alkoxy, or halo.

Each Y in Formula I (I-a or I-b) is independently an alkylene,aralkylene, or a combination thereof. Suitable alkylene groups typicallyhave up to 10 carbon atoms, up to 8 carbon atoms, up to 6 carbon atoms,or up to 4 carbon atoms. Exemplary alkylene groups include methylene,ethylene, propylene, butylene, and the like. Suitable aralkylene groupsusually have an arylene group with 6 to 12 carbon atoms bonded to analkylene group with 1 to 10 carbon atoms. In some exemplary aralkylenegroups, the arylene portion is phenylene. That is, the divalentaralkylene group is phenylene-alkylene where the phenylene is bonded toan alkylene having 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Asused herein with reference to group Y, “a combination thereof” refers toa combination of two or more groups selected from an alkylene andaralkylene group. A combination can be, for example, a single aralkylenebonded to a single alkylene (e.g., alkylene-arylene-alkylene). In oneexemplary alkylene-arylene-alkylene combination, the arylene isphenylene and each alkylene has 1 to 10, 1 to 6, or 1 to 4 carbon atoms.

Each subscript n in Formula I (I-a or I-b) is independently an integerof 0 to 1500. For example, subscript n can be an integer up to 1000, upto 500, up to 400, up to 300, up to 200, up to 100, up to 80, up to 60,up to 40, up to 20, or up to 10. The value of n is often at least 1, atleast 2, at least 3, at least 5, at least 10, at least 20, or at least40. For example, subscript n can be in the range of 40 to 1500, 0 to1000, 40 to 1000, 0 to 500, 1 to 500, 40 to 500, 1 to 400, 1 to 300, 1to 200, 1 to 100, 1 to 80, 1 to 40, or 1 to 20.

The subscript p is an integer of 1 to 10. For example, the value of p isoften an integer up to 9, up to 8, up to 7, up to 6, up to 5, up to 4,up to 3, or up to 2. The value of p can be in the range of 1 to 8, 1 to6, or 1 to 4.

Group G in Formula I (I-a or I-b) is a residual unit that is equal toone or more amine compounds of the formula G(NHR³)_(q) minus the q aminogroups (i.e., —NHR³ groups), where q is an integer greater than 2. Asdiscussed hereinabove, the branched copolymer can additionally includedifferent repeat units such as, for example, repeat units of Formula I,but wherein q is equal to 2. The one or more amine compounds can haveprimary and/or secondary amino groups. Group R³ is hydrogen or alkyl(e.g., an alkyl having 1 to 10, 1 to 6, or 1 to 4 carbon atoms) or R³taken together with G and with the nitrogen to which they are bothattached forms a heterocyclic group (e.g., R³HN-G-NHR³ is piperazine).In most embodiments, R³ is hydrogen or an alkyl. In many embodiments,all of the amino groups of the one or more amine compounds are primaryamino groups (i.e., all the R³ groups are hydrogen) and the one or moreamine compounds are of the formula G(NH₂)_(q).

In certain embodiments, the one or more amine compounds are a mixture of(i) a diamine compound of formula R³HN-G-NHR³ and (ii) a polyaminecompound of formula G(NHR³)_(q), where q is an integer greater than 2.In such embodiments, the polyamine compound of formula G(NHR³)_(q) canbe, but is not limited to, triamine compounds (i.e., q=3), tetraaminecompounds (i.e., q=4), and combinations thereof. In such embodiments,the number of equivalents of polyamine (ii) per equivalent of diamine(i) is preferably at least 0.001, more preferably at least 0.005, andmost preferably at least 0.01. In such embodiments, the number ofequivalents of polyamine (ii) per equivalent of diamine (i) ispreferably at most 3, more preferably at most 2, and most preferably atmost 1.

When G includes residual units that are equal to (i) a diamine compoundof formula R³HN-G-NHR³ minus the two amino groups (i.e., —NHR³ groups),G can be an alkylene, heteroalkylene, polydiorganosiloxane, arylene,aralkylene, or a combination thereof. Suitable alkylenes often have 2 to10, 2 to 6, or 2 to 4 carbon atoms. Exemplary alkylene groups includeethylene, propylene, butylene, and the like. Suitable heteroalkylenesare often polyoxyalkylenes such as polyoxyethylene having at least 2ethylene units, polyoxypropylene having at least 2 propylene units, orcopolymers thereof. Suitable polydiorganosiloxanes include thepolydiorganosiloxane diamines of Formula III, which are described below,minus the two amino groups. Exemplary polydiorganosiloxanes include, butare not limited to, polydimethylsiloxanes with alkylene Y groups.Suitable aralkylene groups usually contain an arylene group having 6 to12 carbon atoms bonded to an alkylene group having 1 to 10 carbon atoms.Some exemplary aralkylene groups are phenylene-alkylene where thephenylene is bonded to an alkylene having 1 to 10 carbon atoms, 1 to 8carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. As usedherein with reference to group G, “a combination thereof” refers to acombination of two or more groups selected from an alkylene,heteroalkylene, polydiorganosiloxane, arylene, and aralkylene. Acombination can be, for example, an aralkylene bonded to an alkylene(e.g., alkylene-arylene-alkylene). In one exemplaryalkylene-arylene-alkylene combination, the arylene is phenylene and eachalkylene has 1 to 10, 1 to 6, or 1 to 4 carbon atoms.

In preferred embodiments, the polydiorganosiloxane polyamide is abranched polydiorganosiloxane polyoxamide. The branchedpolydiorganosiloxane polyamide tends to be free of groups having aformula —R^(a)—(CO)—NH— where R^(a) is an alkylene. All of thecarbonylamino groups along the backbone of the copolymeric material arepart of an oxalylamino group (i.e., the —(CO)—(CO)—NH— group). That is,any carbonyl group along the backbone of the copolymeric material isbonded to another carbonyl group and is part of an oxalyl group. Morespecifically, the branched polydiorganosiloxane polyoxamide has aplurality of aminoxalylamino groups.

The polydiorganosiloxane polyamide is a branched, block copolymer andcan be an elastomeric material. Unlike many of the knownpolydiorganosiloxane polyamides that are generally formulated as brittlesolids or hard plastics, the polydiorganosiloxane polyamides can beformulated to include greater than 50 weight percentpolydiorganosiloxane segments based on the weight of the copolymer. Theweight percent of the diorganosiloxane in the polydiorganosiloxanepolyamides can be increased by using higher molecular weightpolydiorganosiloxanes segments to provide greater than 60 weightpercent, greater than 70 weight percent, greater than 80 weight percent,greater than 90 weight percent, greater than 95 weight percent, orgreater than 98 weight percent of the polydiorganosiloxane segments inthe polydiorganosiloxane polyamides. Higher amounts of thepolydiorganosiloxane can be used to prepare elastomeric materials withlower modulus while maintaining reasonable strength.

Some of the polydiorganosiloxane polyamides can be heated to atemperature up to 200° C., up to 225° C., up to 250° C., up to 275° C.,or up to 300° C. without noticeable degradation of the material. Forexample, when heated in a thermogravimetric analyzer in the presence ofair, the copolymers often have less than a 10 percent weight loss whenscanned at a rate 50° C. per minute in the range of 20° C. to 350° C.Additionally, the copolymers can often be heated at a temperature suchas 250° C. for 1 hour in air without apparent degradation as determinedby no detectable loss of mechanical strength upon cooling.

The copolymeric material having repeat units of Formula I (I-a or I-b)can be optically clear. As used herein, the term “optically clear”refers to a material that is clear to the human eye. An optically clearcopolymeric material often has a luminous transmission of at least 90percent, a haze of less than 2 percent, and opacity of less than 1percent in the 400 to 700 nm wavelength range. Both the luminoustransmission and the haze can be determined using, for example, themethod of ASTM-D 1003-95.

Additionally, the copolymeric material having repeat units of Formula I(I-a or I-b) can have a low refractive index. As used herein, the term“refractive index” refers to the absolute refractive index of a material(e.g., copolymeric material) and is the ratio of the speed ofelectromagnetic radiation in free space to the speed of theelectromagnetic radiation in the material of interest. Theelectromagnetic radiation is white light. The index of refraction ismeasured using an Abbe refractometer, available commercially, forexample, from Fisher Instruments of Pittsburgh, Pa. The measurement ofthe refractive index can depend, to some extent, on the particularrefractometer used. For some embodiments (e.g., embodiments in which thecopolymer includes a polydimethylsiloxane segment), the copolymericmaterial can have a refractive index in the range of 1.41 to 1.50. Forsome other embodiments (e.g., embodiments in which the copolymerincludes a polyphenylsiloxane or a polydiphenylsiloxane segment), thecopolymeric material can have a refractive index in the range of from1.46 to 1.55.

Methods of Making Polydiorganosiloxane Polyamide Copolymers

The branched block copolymers having repeat units of Formula I-a or I-bcan be prepared, for example, as represented in Reaction Schemes A-1 andA-2, respectively.

In this reaction scheme, a precursor of Formula II (II-a or II-b) iscombined under reaction conditions with one or more amine compoundshaving primary and/or secondary amine groups and having a formulaG(NHR³)_(q), where q is an integer greater than 2. Optionally,additional amine compounds (e.g., diamines) can also be combined, suchthat the one or more amine compounds and the additional amine compoundshave on average a formula G(NHR³)_(r), where r is a number greater than2. For example, r can be equal to a number such as 2.001, 2.002, 2.005,2.01, 2.1, 2.5, 3, or even higher. Group R³ is hydrogen or alkyl (e.g.,an alkyl having 1 to 10, 1 to 6, or 1 to 4 carbon atoms) or R³ takentogether with G and with the nitrogen to which they are both attachedforms a heterocyclic group (e.g., R³HN-G-NHR³ is piperazine). In mostembodiments, R³ is hydrogen or an alkyl. In many embodiments, all of theamino groups of the one or more amine compounds are primary amino groups(i.e., all the R³ groups are hydrogen) and the one or more aminecompounds are of the formula G(NH₂)_(q). The R²OH by-product istypically removed from the resulting polydiorganosiloxane polyamide.

In certain embodiments, the one or more amine compounds and any optionaladditional amine compounds are a mixture of (i) a diamine compound offormula R³HN-G-NHR³ and (ii) a polyamine compound of formulaG(NHR³)_(q), where q is greater than 2. In such embodiments, thepolyamine compound of formula G(NHR³)_(q) can be, but is not limited to,triamine compounds (i.e., q=3), tetraamine compounds (i.e., q=4), andcombinations thereof. In such embodiments, the number of equivalents ofpolyamine (ii) per equivalent of diamine (i) is preferably at least0.001, more preferably at least 0.005, and most preferably at least0.01. In such embodiments, the number of equivalents of polyamine (ii)per equivalent of diamine (i) is preferably at most 3, more preferablyat most 2, and most preferably at most 1.

Exemplary triamines include, but are not limited to,tris(2-aminoethyl)amine, diethylentriamine, polyoxyalkylene triaminessuch as those available, for example, from Huntsman (The Woodlands,Tex.) under the trade designations JEFFAMINE T-3000 (i.e.,polyoxypropropylene triamine having an average molecular weight of 3000g/mole) and JEFFAMINE T-5000 (i.e., polyoxypropropylene triamine havingan average molecular weight of 5000 g/mole), amino-functionalpolysiloxanes, and combinations thereof. Exemplary tetraamines include,but are not limited to, triethylene tetraamine Exemplarypolydimethylsiloxanes having amino functionality include, for example,polydimethylsiloxane copolymers having aminopropylmethylsiloxane unitssuch as those available under the trade designations AMS-132, AMS-152,and AMS-162 from Gelest, Inc., Morrisville, Pa.

When the one or more amine compounds are present in a mixture thatincludes diamines, the diamines are sometimes classified as organicdiamines or polydiorganosiloxane diamines with the organic diaminesincluding, for example, those selected from alkylene diamines,heteroalkylene diamines, arylene diamines, aralkylene diamines, oralkylene-aralkylene diamines Tertiary amines that do not react with theprecursor of Formula II (II-a or II-b) can be present. Additionally, thediamine is free of any carbonylamino group. That is, the diamine is notan amide.

Exemplary polyoxyalkylene diamines (i.e., G is a heteroalkylene with theheteroatom being oxygen) include, but are not limited to, thosecommercially available from Huntsman, The Woodlands, Tex. under thetrade designation JEFFAMINE D-230 (i.e., polyoxypropropylene diaminehaving an average molecular weight of 230 g/mole), JEFFAMINE D-400(i.e., polyoxypropylene diamine having an average molecular weight of400 g/mole), JEFFAMINE D-2000 (i.e., polyoxypropylene diamine having anaverage molecular weight of 2,000 g/mole), JEFFAMINE HK-511 (i.e.,polyetherdiamine with both oxyethylene and oxypropylene groups andhaving an average molecular weight of 220 g/mole), JEFFAMINE ED-2003(i.e., polypropylene oxide capped polyethylene glycol having an averagemolecular weight of 2,000 g/mole), and JEFFAMINE EDR-148 (i.e.,triethyleneglycol diamine).

Exemplary alkylene diamines (i.e., G is a alkylene) include, but are notlimited to, ethylene diamine, propylene diamine, butylene diamine,hexamethylene diamine, 2-methylpentamethylene 1,5-diamine (i.e.,commercially available from DuPont, Wilmington, Del. under the tradedesignation DYTEK A), 1,3-pentane diamine (commercially available fromDuPont under the trade designation DYTEK EP), 1,4-cyclohexane diamine,1,2-cyclohexane diamine (commercially available from DuPont under thetrade designation DHC-99), 4,4′-bis(aminocyclohexyl)methane, and3-aminomethyl-3,5,5-trimethylcyclohexylamine.

Exemplary arylene diamines (i.e., G is an arylene such as phenylene)include, but are not limited to, m-phenylene diamine, o-phenylenediamine, and p-phenylene diamine Exemplary aralkylene diamines (i.e., Gis an aralkylene such as alkylene-phenyl) include, but are not limitedto 4-aminomethyl-phenylamine, 3-aminomethyl-phenylamine, and2-aminomethyl-phenylamine Exemplary alkylene-aralkylene diamines (i.e.,G is an alkylene-aralkylene such as alkylene-phenylene-alkylene)include, but are not limited to, 4-aminomethyl-benzylamine,3-aminomethyl-benzylamine, and 2-aminomethyl-benzylamine.

The precursor of Formulas II-a and II-b in Reaction Schemes A-1 and A-2,respectively have at least one polydiorganosiloxane segment and at leasttwo amido groups (e.g., oxalylamino groups). Group R¹, group Y,subscript n, and subscript p are the same as described for Formula I(I-a or I-b). Each group R² is independently an alkyl, haloalkyl, aryl,or aryl substituted with an alkyl, alkoxy, halo, or alkoxycarbonyl. Theprecursor of Formula II (II-a or II-b) can include a single compound(i.e., all the compounds have the same value of p and n) or can includea plurality of compounds (i.e., the compounds have different values forp, different values for n, or different values for both p and n).Precursors with different n values have siloxane chains of differentlength. Precursors having a p value of at least 2 are chain extended.

In some embodiments, the precursor is a mixture of a first compound ofFormula II (II-a and/or II-b) with subscript p equal to 1 and a secondcompound of Formula II (II-a and/or II-b) with subscript p equal to atleast 2. The first compound can include a plurality of differentcompounds with different values of n. The second compound can include aplurality of compounds with different values of p, different values ofn, or different values of both p and n. Mixtures can include at least 50weight percent of the first compound of Formula II (II-a or II-b) (i.e.,p is equal to 1) and no greater than 50 weight percent of the secondcompound of Formula II (II-a or II-b) (i.e., p is equal to at least 2)based on the sum of the weight of the first and second compounds in themixture. In some mixtures, the first compound is present in an amount ofat least 55 weight percent, at least 60 weight percent, at least 65weight percent, at least 70 weight percent, at least 75 weight percent,at least 80 weight percent, at least 85 weight percent, at least 90weight percent, at least 95 weight percent, or at least 98 weightpercent based on the total amount of the compounds of Formula II. Themixtures often contain no greater than 50 weight percent, no greaterthan 45 weight percent, no greater than 40 weight percent, no greaterthan 35 weight percent, no greater than 30 weight percent, no greaterthan 25 weight percent, no greater than 20 weight percent, no greaterthan 15 weight percent, no greater than 10 weight percent, no greaterthan 5 weight percent, or no greater than 2 weight percent of the secondcompound.

Different amounts of the chain-extended precursor of Formula II (II-a orII-b) in the mixture can affect the final properties of the elastomericmaterial having repeat units of Formula I (I-a or I-b). That is, theamount of the second compound of Formula II (II-a or II-b) (i.e., pequal to at least 2) can be varied advantageously to provide elastomericmaterials with a range of properties. For example, a higher amount ofthe second compound of Formula II (II-a or II-b) can alter the meltrheology (e.g., the elastomeric material can flow easier when present asa melt), alter the softness of the elastomeric material, lower themodulus of the elastomeric material, or a combination thereof.

Reaction Schemes A-1 and A-2 can be conducted using a plurality ofprecursors of Formulas II-a and II-b, respectively, a plurality of aminecompounds, or a combination thereof. A plurality of precursors havingdifferent average molecular weights can be combined under reactionconditions with a single amine compound or a mixture of amine compounds(e.g., one or more polyamines and optionally one or more diamines). Forexample, the precursor of Formula II (II-a or II-b) may include amixture of materials with different values of n, different values of p,or different values of both n and p. The multiple amine compounds caninclude, for example, a first polyamine that is an organic polyamine anda second amine compound such as a polydiorganosiloxane diamine Likewise,a single precursor can be combined under reaction conditions withmultiple amine compounds.

The molar ratio of the precursor of Formula II (II-a or II-b) to the oneor more amine compounds is often 1:1. For example, the molar ratio isoften less than or equal to 1:0.80, less than or equal to 1:0.85, lessthan or equal to 1:0.90, less than or equal to 1:0.95, or less than orequal to 1:1. The molar ratio is often greater than or equal to 1:1.05,greater than or equal to 1:1.10, or greater than or equal to 1:1.15. Forexample, the molar ratio can be in the range of 1:0.80 to 1:1.20, in therange of 1:0.80 to 1:1.15, in the range of 1:0.80 to 1:1.10, in therange of 1:0.80 to 1:1.05, in the range of 1:0.90 to 1:1.10, or in therange of 1:0.95 to 1:1.05. Alternatively, the molar ratio of theprecursor of Formula II to the one or more amine compounds can be lessthan 1:1.20 or greater than 1:0.80. For example, it can be 1:0.50,1:0.55, 1:0.60, 1:0.65, 1:0.70, or 1:0.75, or it can be 1:1.25, 1:1.30,or 1:1.35. For example, the molar ratio can be in the range of less than1:1.20 down to and including 1:2.00. Alternatively, it can be in therange of greater than 1:0.80 up to and including 1:0.50. Varying themolar ratio can be used, for example, to alter the overall molecularweight, which can effect the rheology of the resulting copolymers.Additionally, varying the molar ratio can be used to provideamide-containing end groups (e.g., oxalylamino-containing end groups) oramino end groups, depending upon which reactant is present in molarexcess.

The condensation reaction of the precursor of Formula II (II-a or II-b)with the one or more amine compounds (i.e., Reaction Scheme A-1 or A-2,respectively) is often conducted at room temperature or at elevatedtemperatures such as at temperatures up to 250° C. For example, thereaction often can be conducted at room temperature or at temperaturesup to 100° C. In other examples, the reaction can be conducted at atemperature of at least 100° C., at least 120° C., or at least 150° C.For example, the reaction temperature is often in the range of 100° C.to 220° C., in the range of 120° C. to 220° C., or in the range of 150°C. to 200° C. The condensation reaction is often complete in less than 1hour, in less than 2 hours, in less than 4 hours, in less than 8 hours,or in less than 12 hours.

Reaction Scheme A-1 or A-2 can occur in the presence or absence of asolvent. Suitable solvents usually do not react with any of thereactants or products of the reactions. Additionally, suitable solventsare usually capable of maintaining all the reactants and all of theproducts in solution throughout the polymerization process. Exemplarysolvents include, but are not limited to, toluene, tetrahydrofuran,dichloromethane, aliphatic hydrocarbons (e.g., alkanes such as hexane),or mixtures thereof.

Any solvent that is present can be stripped from the resultingpolydiorganosiloxane polyamide at the completion of the reaction.Solvents that can be removed under the same conditions used to removethe alcohol by-product are often preferred. The stripping process isoften conducted at a temperature of at least 100° C., at least 125° C.,or at least 150° C. The stripping process is typically at a temperatureless than 300° C., less than 250° C., or less than 225° C.

Conducting Reaction Scheme A-1 or A-2 in the absence of a solvent can bedesirable because only the volatile by-product, R²OH, needs to beremoved at the conclusion of the reaction. Additionally, a solvent thatis not compatible with both reactants and the product can result inincomplete reaction and a low degree of polymerization.

Any suitable reactor or process can be used to prepare the copolymericmaterial according to Reaction Scheme A-1 or A-2. The reaction can beconducted using a batch process, semi-batch process, or a continuousprocess. Exemplary batch processes can be conducted in a reaction vesselequipped with a mechanical stirrer such as a Brabender mixer, providedthe product of the reaction is in a molten state has a sufficiently lowviscosity to be drained from the reactor. Exemplary semi-batch processcan be conducted in a continuously stirred tube, tank, or fluidized bed.Exemplary continuous processes can be conducted in a single screw ortwin screw extruder such as a wiped surface counter-rotating orco-rotating twin screw extruder.

In many processes, the components are metered and then mixed together toform a reaction mixture. The components can be metered volumetrically orgravimetrically using, for example, a gear, piston or progressing cavitypump. The components can be mixed using any known static or dynamicmethod such as, for example, static mixers, or compounding mixers suchas single or multiple screw extruders. The reaction mixture can then beformed, poured, pumped, coated, injection molded, sprayed, sputtered,atomized, stranded or sheeted, and partially or completely polymerized.The partially or completely polymerized material can then optionally beconverted to a particle, droplet, pellet, sphere, strand, ribbon, rod,tube, film, sheet, coextruded film, web, non-woven, microreplicatedstructure, or other continuous or discrete shape, prior to thetransformation to solid polymer. Any of these steps can be conducted inthe presence or absence of applied heat. In one exemplary process, thecomponents can be metered using a gear pump, mixed using a static mixer,and injected into a mold prior to solidification of the polymerizingmaterial.

The polydiorganosiloxane-containing precursor of Formula II-b inReaction Scheme A-2 can be prepared by any known method. In someembodiments, this precursor is prepared according to Reaction Scheme B.

A polydiorganosiloxane diamine of Formula III (p moles) is reacted witha molar excess of an oxalate of Formula IV (greater than p+1 moles)under an inert atmosphere to produce the polydiorganosiloxane-containingprecursor of Formula II and R²—OH by-product. In this reaction, R¹, Y,n, and p are the same as previously described for Formula I (I-a orI-b). Each R² in Formula IV is independently an alkyl, haloalkyl, aryl,or aryl substituted with an alkyl, alkoxy, halo, or alkoxycarbonyl. Thepreparation of the precursor of Formula II according to Reaction SchemeB is further described in U.S. patent application Ser. No. 11/317,616,filed 23 Dec. 2005.

The polydiorganosiloxane diamine of Formula III in Reaction Scheme B canbe prepared by any known method and can have any suitable molecularweight, such as an average molecular weight in the range of 700 to150,000 g/mole. Suitable polydiorganosiloxane diamines and methods ofmaking the polydiorganosiloxane diamines are described, for example, inU.S. Pat. Nos. 3,890,269 (Martin), 4,661,577 (Jo Lane et al.), 5,026,890(Webb et al.), 5,276,122 (Aoki et al.), 5,214,119 (Leir et al.),5,461,134 (Leir et al.), 5,512,650 (Leir et al.), and 6,355,759 (Shermanet al.). Some polydiorganosiloxane diamines are commercially available,for example, from Shin Etsu Silicones of America, Inc., Torrance, Calif.and from Gelest Inc., Morrisville, Pa.

A polydiorganosiloxane diamine having a molecular weight greater than2,000 g/mole or greater than 5,000 g/mole can be prepared using themethods described in U.S. Pat. Nos. 5,214,119 (Leir et al.), 5,461,134(Leir et al.), and 5,512,650 (Leir et al.). One of the described methodsinvolves combining under reaction conditions and under an inertatmosphere (a) an amine functional end blocker of the following formula

where Y and R¹ are the same as defined for Formula I (I-a or I-b); (b)sufficient cyclic siloxane to react with the amine functional endblocker to form a polydiorganosiloxane diamine having a molecular weightless than 2,000 g/mole; and (c) an anhydrous aminoalkyl silanolatecatalyst of the following formula

where Y and R¹ are the same as defined in Formula I (I-a or I-b) and M⁺is a sodium ion, potassium ion, cesium ion, rubidium ion, ortetramethylammonium ion. The reaction is continued until substantiallyall of the amine functional end blocker is consumed and then additionalcyclic siloxane is added to increase the molecular weight. Theadditional cyclic siloxane is often added slowly (e.g., drop wise). Thereaction temperature is often conducted in the range of 80° C. to 90° C.with a reaction time of 5 to 7 hours. The resulting polydiorganosiloxanediamine can be of high purity (e.g., less than 2 weight percent, lessthan 1.5 weight percent, less than 1 weight percent, less than 0.5weight percent, less than 0.1 weight percent, less than 0.05 weightpercent, or less than 0.01 weight percent silanol impurities). Alteringthe ratio of the amine end functional blocker to the cyclic siloxane canbe used to vary the molecular weight of the resultingpolydiorganosiloxane diamine of Formula III.

Another method of preparing the polydiorganosiloxane diamine of FormulaIII includes combining under reaction conditions and under an inertenvironment (a) an amine functional end blocker of the following formula

where R¹ and Y are the same as described for Formula I (I-a or I-b) andwhere the subscript x is equal to an integer of 1 to 150; (b) sufficientcyclic siloxane to obtain a polydiorganosiloxane diamine having anaverage molecular weight greater than the average molecular weight ofthe amine functional end blocker; and (c) a catalyst selected fromcesium hydroxide, cesium silanolate, rubidium silanolate, cesiumpolysiloxanolate, rubidium polysiloxanolate, and mixtures thereof. Thereaction is continued until substantially all of the amine functionalend blocker is consumed. This method is further described in U.S. Pat.No. 6,355,759 B1 (Sherman et al.). This procedure can be used to prepareany molecular weight of the polydiorganosiloxane diamine.

Yet another method of preparing the polydiorganosiloxane diamine ofFormula III is described in U.S. Pat. No. 6,531,620 B2 (Brader et al.).In this method, a cyclic silazane is reacted with a siloxane materialhaving hydroxy end groups as shown in the following reaction.

The groups R¹ and Y are the same as described for Formula I (I-a orI-b). The subscript m is an integer greater than 1.

Examples of polydiorganosiloxane diamines include, but are not limitedto, polydimethylsiloxane diamine, polydiphenylsiloxane diamine,polytrifluoropropylmethylsiloxane diamine, polyphenylmethylsiloxanediamine, polydiethylsiloxane diamine, polydivinylsiloxane diamine,polyvinylmethylsiloxane diamine, poly(5-hexenyl)methylsiloxane diamine,and mixtures thereof.

In Reaction Scheme B, an oxalate of Formula IV is reacted with thepolydiorganosiloxane diamine of Formula III under an inert atmosphere.The two R² groups in the oxalate of Formula IV can be the same ordifferent. In some methods, the two R² groups are different and havedifferent reactivity with the polydiorganosiloxane diamine of FormulaIII in Reaction Scheme B.

Group R² can be an alkyl, haloalkyl, aryl, or aryl substituted with analkyl, alkoxy, halo, or alkoxycarbonyl. Suitable alkyl and haloalkylgroups for R² often have 1 to 10, 1 to 6, or 1 to 4 carbon atoms.Although tertiary alkyl (e.g., tert-butyl) and haloalkyl groups can beused, there is often a primary or secondary carbon atom attacheddirectly (i.e., bonded) to the adjacent oxy group. Exemplary alkylgroups include methyl, ethyl, n-propyl, iso-propyl, n-butyl, andiso-butyl. Exemplary haloalkyl groups include chloroalkyl groups andfluoroalkyl groups in which some, but not all, of the hydrogen atoms onthe corresponding alkyl group are replaced with halo atoms. For example,the chloroalkyl or a fluoroalkyl groups can be chloromethyl,2-chloroethyl, 2,2,2-trichloroethyl, 3-chloropropyl, 4-chlorobutyl,fluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl, 3-fluoropropyl,4-fluorobutyl, and the like. Suitable aryl groups for R² include thosehaving 6 to 12 carbon atoms such as, for example, phenyl. An aryl groupcan be unsubstituted or substituted with an alkyl (e.g., an alkyl having1 to 4 carbon atoms such as methyl, ethyl, or n-propyl), an alkoxy(e.g., an alkoxy having 1 to 4 carbon atoms such as methoxy, ethoxy, orpropoxy), halo (e.g., chloro, bromo, or fluoro), or alkoxycarbonyl(e.g., an alkoxycarbonyl having 2 to 5 carbon atoms such asmethoxycarbonyl, ethoxycarbonyl, or propoxycarbonyl).

The oxalates of Formula IV in Reaction Scheme B can be prepared, forexample, by reaction of an alcohol of formula R²—OH with oxalyldichloride. Commercially available oxalates of Formula IV (e.g., fromSigma-Aldrich, Milwaukee, Wis. and from VWR International, Bristol,Conn.) include, but are not limited to, dimethyl oxalate, diethyloxalate, di-n-butyl oxalate, di-tert-butyl oxalate, bis(phenyl)oxalate,bis(pentafluorophenyl) oxalate,1-(2,6-difluorophenyl)-2-(2,3,4,5,6-pentachlorophenyl) oxalate, andbis(2,4,6-trichlorophenyl) oxalate.

A molar excess of the oxalate is used in Reaction Scheme B. That is, themolar ratio of oxalate to polydiorganosiloxane diamine is greater thanthe stoichiometric molar ratio, which is (p+1): p. The molar ratio isoften greater than 2:1, greater than 3:1, greater than 4:1, or greaterthan 6:1. The condensation reaction typically occurs under an inertatmosphere and at room temperature upon mixing of the components.

The condensation reaction used to produce the precursor of Formula II(i.e., Reaction Scheme B) can occur in the presence or absence of asolvent. In some methods, no solvent or only a small amount of solventis included in the reaction mixture. In other methods, a solvent may beincluded such as, for example, toluene, tetrahydrofuran,dichloromethane, or aliphatic hydrocarbons (e.g., alkanes such ashexane).

Removal of excess oxalate from the precursor of Formula II prior toreaction with the diamine in Reaction Scheme A tends to favor formationof an optically clear polydiorganosiloxane polyamide. The excess oxalatecan typically be removed from the precursor using a stripping process.For example, the reacted mixture (i.e., the product or products of thecondensation reaction according to Reaction Scheme B) can be heated to atemperature up to 150° C., up to 175° C., up to 200° C., up to 225° C.,or up to 250° C. to volatilize the excess oxalate. A vacuum can bepulled to lower the temperature that is needed for removal of the excessoxalate. The precursor compounds of Formula II tend to undergo minimalor no apparent degradation at temperatures in the range of 200° C. to250° C. or higher. Any other known methods of removing the excessoxalate can be used.

The by-product of the condensation reaction shown in Reaction Scheme Bis an alcohol (i.e., R²—OH is an alcohol). Group R² is often limited toan alkyl having 1 to 4 carbon atoms, a haloalkyl having 1 to 4 carbonatoms, or an aryl such as phenyl that form an alcohol that can bereadily removed (e.g., vaporized) by heating at temperatures no greaterthan 250° C. Such an alcohol can be removed when the reacted mixture isheated to a temperature sufficient to remove the excess oxalate ofFormula IV.Compositions and Constructions

The branched polydiorganosiloxane polyamide copolymers can be blendedwith one or more other polymers (e.g., organic polymer components) suchas a hot melt processable thermoplastic polymer (which may beelastomeric or nonelastomeric), a hot melt processable elastomericthermoset polymer, a silicone polymer, and mixtures thereof.

The organic polymer may be solvent or melt mixed with the branchedpolydiorganosiloxane polyamide segmented copolymer. The organic polymermay be a polydiorganosiloxane polyamide-containing component or apolymer that does not contain polydiorganosiloxane segments.

Examples of suitable polydiorganosiloxane polyamide-containingcomponents include linear polydiorganosiloxane polyamide copolymers. Anexemplary copolymeric material contains at least two repeat units ofFormula V-a:

In this formula, each R¹ is independently an alkyl, haloalkyl, aralkyl,alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo. EachY is independently an alkylene, aralkylene, or a combination thereof.Subscript n is independently an integer of 0 to 1500 and subscript p isan integer of 1 to 10. Group G is a divalent group that is the residueunit that is equal to a diamine of formula R³HN-G-NHR³ minus the two—NHR³ groups (i.e., amino groups). Group R³ is hydrogen or alkyl or R³taken together with G and with the nitrogen to which they are bothattached forms a heterocyclic group. Each B is independently a covalentbond, an alkylene of 4-20 carbons, an aralkylene, an arylene, or acombination thereof. Each asterisk indicates the position of attachmentof the repeating unit to another group such as another repeat unit.

A preferred copolymeric material contains at least two repeat units ofFormula V-b:

In this formula, each R¹ is independently an alkyl, haloalkyl, aralkyl,alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo. EachY is independently an alkylene, aralkylene, or a combination thereof.Subscript n is independently an integer of 0 to 1500 and subscript p isan integer of 1 to 10. Group G is a divalent group that is the residueunit that is equal to a diamine of formula R³HN-G-NHR³ minus the two—NHR³ groups (i.e., amino groups). Group R³ is hydrogen or alkyl or R³taken together with G and with the nitrogen to which they are bothattached forms a heterocyclic group. Each asterisk indicates theposition of attachment of the repeating unit to another group such asanother repeat unit.

Thermoplastic materials useful in the present invention that aregenerally considered nonelastomeric include, for example, polyolefinssuch as isotactic polypropylene, low density polyethylene, linear lowdensity polyethylene, very low density polyethylene, medium densitypolyethylene, high density polyethylene, polybutylene, nonelastomericpolyolefin copolymers or terpolymers, such as ethylene/propylenecopolymer and blends thereof; ethylene-vinyl acetate copolymers such asthat available under the trade designation ELVAX 260, available fromDuPont Chemical Co.; ethylene acrylic acid copolymers; ethylenemethacrylic acid copolymers such as that available under the tradedesignation SURLYN 1702, available from DuPont Chemical Co.;polymethylmethacrylate; polystyrene; ethylene vinyl alcohol; polyester;amorphous polyester; polyamides; fluorinated thermoplastics, such apolyvinylidene fluoride, polytetrafluoroethylene, fluorinatedethylene/propylene copolymers and fluorinated ethylene/propylenecopolymers; halogenated thermoplastics, such as a chlorinatedpolyethylene. Any single thermoplastic material can be mixed with atleast one branched polydiorganosiloxane polyamide-containing component.Alternatively, a mixture of thermoplastic materials may be used.

Thermoplastic materials that have elastomeric properties are typicallycalled thermoplastic elastomeric materials. Thermoplastic elastomericmaterials are generally defined as materials that act as though theywere covalently cross-linked, exhibiting high resilience and low creep,yet flow when heated above their softening point. Thermoplasticelastomeric materials useful in the present invention include, forexample, linear, radial, star and tapered styrene-isoprene blockcopolymers such as that available under the trade designation KRATOND1107P from Shell Chemical Co. of Houston, Tex. and that available underthe trade designation EUROPRENE SOL TE 9110 from EniChem ElastomersAmericas, Inc. of Houston, Tex.; linear styrene-(ethylene-butylene)block copolymers such as that available under the trade designationKRATON G1657 from Shell Chemical Co.; linearstyrene-(ethylene-propylene) block copolymers such as that availableunder the trade designation KRATON G1657X from Shell Chemical Co.;linear, radial, and star styrene-butadiene block copolymers such as thatavailable under the trade designation KRATON D1118X from Shell ChemicalCo. and that available under the trade designation EUROPRENE SOL TE 6205from EniChem Elastomers Americas, Inc.; polyetheresters such as thatavailable under the trade designation HYTREL G3548 from DuPont,elastomeric ethylene-propylene copolymers; thermoplastic elastomericpolyurethanes such as that available under the trade designationMORTHANE URETHENE PE44-203 from Morton International, Inc., Chicago,Ill.; self-tacky or tackified polyacrylates including C₃ to C₁₂alkylesters that may contain other comonomers, such as for example,isooctyl acrylate and from 0 to 20 weight percent acrylic acid;polyvinylethers; poly-α-olefin-based thermoplastic elastomeric materialssuch as those represented by the formula —(CH₂CHR)_(x) where R is analkyl group containing 2 to 10 carbon atoms and poly-α-olefins based onmetallocene catalysis such as that available under the trade designationENGAGE EG8200, an ethylene/poly-α-olefin copolymer, available from DowPlastics Co. of Midland, Mich.; as well as polydiorganosiloxanepolyurea-urethanes, available from Wacker Chemie AG, Germany under thetrade designation GENIOMER.

Thermoset elastomers (i.e., elastomeric thermosets) are materials thatchange irreversibly under the influence of heat from a fusible andsoluble material into one that is infusible and insoluble through theformation of a covalently cross-linked, thermally stable network.Thermoset elastomers useful in the present invention include, forexample, natural rubbers such as CV-60, a controlled viscosity gradeavailable from Goodyear Chemical, Akron, Ohio, and SMR-5, a ribbedsmoked sheet rubber; butyl rubbers, such as Exxon Butyl 268 availablefrom Exxon Chemical Co.; synthetic polyisoprenes such as that availableunder the trade designation CARIFLEX IR309 from Royal Dutch Shell ofNetherlands and that available under the trade designation NATSYN 2210from Goodyear Tire and Rubber Co.; styrene-butadiene random copolymerrubbers such as that available under the trade designation AMERIPOL1011A from BF Goodrich of Akron, Ohio; polybutadienes; polyisobutylenessuch as that available under the trade designation VISTANEX MM L-80 fromExxon Chemical Co.; polyurethanes such as, for example, polyoctadecylcarbamate disclosed in U.S. Pat. No. 2,532,011 (Dahlquist et al.);amorphous poly-α-olefins such as C₄-C₁₀ linear or branchedpoly-α-olefins; polydiorganosiloxane polyurea-containing components,such as those disclosed in U.S. Pat. No. 5,214,119 (Leir et al.).

Suitable silicone polymers are typically fluids and may be curable(through incorporation of suitable functional groups such as hydroxylgroups or ethylenically unsaturated groups, e.g., acrylate groups) orsubstantially noncurable. Examples of suitable silicone fluids aredescribed in, for example, International Publication No. WO 97/40103,U.S. Pat. No. 6,441,118, U.S. Pat. No. 5,091,483, and U.S. Pat. Pub. No.2005/0136266. Particularly preferred silicone polymers aremoisture-curable silicone fluids, e.g., hydroxyl-terminatedpolydiorganosiloxanes or nonreactive silicone fluids such as thatavailable under the trade designation 47V1000 RHODORSIL from RhodiaSilicones. Any of the hydroxyl-terminated polydiorganosiloxanestypically used in known silicone sealing and adhesive compositions maybe used in the compositions of the present invention. Examples ofsuitable commercially available silicone fluids include those availableunder the trade designation MASIL from Lubruzol Corp. (Ohio) and WackerChemie AG (Germany).

Compositions and constructions as disclosed herein can also includefunctional components. Functional components such as antistaticadditives, ultraviolet light absorbers (UVAs), hindered amine lightstabilizers (HALS), dyes, colorants, pigments, antioxidants, slipagents, low adhesion materials, conductive materials, abrasion resistantmaterials, optical elements, dimensional stabilizers, adhesives,tackifiers, flame retardants, phosphorescent materials, fluorescentmaterials, nanoparticles, anti-graffiti agents, dew-resistant agents,load bearing agents, silicate resins, fumed silica, glass beads, glassbubbles, glass fibers, mineral fibers, clay particles, organic fibers,e.g., nylon, KEVLAR, metal particles, and the like which can be added inamounts up to 100 parts per 100 parts of the sum of the branchedpolydiorganosiloxane polyamide segmented polymeric component, providedthat if and when incorporated, such additives are not detrimental to thefunction and functionality of the final polymer product. Other additivessuch as light diffusing materials, light absorptive materials andoptical brighteners, flame retardants, stabilizers, antioxidants,compatibilizers, antimicrobial agents such as zinc oxide, electricalconductors, thermal conductors such as aluminum oxide, boron nitride,aluminum nitride, and nickel particles, including organic and/orinorganic particles, or any number or combination thereof can be blendedinto these systems. The functional components listed above may also beincorporated into polydiorganosiloxane polyamide block copolymerprovided such incorporation does not adversely affect any of theresulting product to an undesirable extent.

Fillers, tackifiers, plasticizers, and other property modifiers may beincorporated in the branched, polydiorganosiloxane polyamide segmentedorganic polymer. Tackifying materials or plasticizers useful with thepolymeric materials are preferably miscible at the molecular level,e.g., soluble in, any or all of the polymeric segments of theelastomeric material or the thermoplastic elastomeric material. Thesetackifying materials or plasticizers are generally immiscible with thepolydiorganosiloxane polyamide-containing component. When the tackifyingmaterial is present it generally comprises 5 to 300 parts by weight,more typically up to 200 parts by weight, based on 100 parts by weightof the polymeric material. Examples of tackifiers suitable for theinvention include but are not limited to liquid rubbers, hydrocarbonresins, rosin, natural resins such as dimerized or hydrogenated balsamsand esterified abietic acids, polyterpenes, terpene phenolics,phenol-formaldehyde resins, and rosin esters. Examples of plasticizersinclude but are not limited to polybutene, paraffinic oils, petrolatum,and certain phthalates with long aliphatic side chains such asditridecyl phthalate.

Either pressure sensitive adhesives or heat activated adhesives can beformulated by combining the polydiorganosiloxane polyoxamides with atackifier such as a silicate tackifying resin. As used herein, the term“pressure sensitive adhesive” refers to an adhesive that possesses thefollowing properties: (1) aggressive and permanent tack; (2) adherenceto a substrate with no more than finger pressure; (3) sufficient abilityto hold onto an adherend; and (4) sufficient cohesive strength to beremoved cleanly from the adherend. As used herein, the term “heatactivated adhesive” refers to an adhesive composition that isessentially non-tacky at room temperature but that becomes tacky aboveroom temperature above an activation temperature such as above 30° C.Heat activated adhesives typically have the properties of a pressuresensitive adhesive above the activation temperature.

Tackifying resins such as silicate tackifying resins are added to thepolydiorganosiloxane polyoxamide copolymer to provide or enhance theadhesive properties of the copolymer. The silicate tackifying resin caninfluence the physical properties of the resulting adhesive composition.For example, as silicate tackifying resin content is increased, theglassy to rubbery transition of the adhesive composition occurs atincreasingly higher temperatures. In some exemplary adhesivecompositions, a plurality of silicate tackifying resins can be used toachieve desired performance.

Suitable silicate tackifying resins include those resins composed of thefollowing structural units M (i.e., monovalent R′₃SiO_(1/2) units), D(i.e., divalent R′₂SiO_(2/2) units), T (i.e., trivalent R′SiO_(3/2)units), and Q (i.e., quaternary SiO_(4/2) units), and combinationsthereof. Typical exemplary silicate resins include MQ silicatetackifying resins, MQD silicate tackifying resins, and MQT silicatetackifying resins. These silicate tackifying resins usually have anumber average molecular weight in the range of 100 to 50,000 or in therange of 500 to 15,000 and generally have methyl R′ groups.

MQ silicate tackifying resins are copolymeric resins having R′₃SiO_(1/2)units (“M” units) and SiO_(4/2) units (“Q” units), where the M units arebonded to the Q units, each of which is bonded to at least one other Qunit. Some of the SiO_(4/2) units (“Q” units) are bonded to hydroxylradicals resulting in HOSiO_(3/2) units (“T^(OH)” units), therebyaccounting for the silicon-bonded hydroxyl content of the silicatetackifying resin, and some are bonded only to other SiO_(4/2) units.

Such resins are described in, for example, Encyclopedia of PolymerScience and Engineering, vol. 15, John Wiley & Sons, New York, (1989),pp. 265-270, and U.S. Pat. Nos. 2,676,182 (Daudt et al.), 3,627,851(Brady), 3,772,247 (Flannigan), and 5,248,739 (Schmidt et al.). Otherexamples are disclosed in U.S. Pat. No. 5,082,706 (Tangney). Theabove-described resins are generally prepared in solvent. Dried orsolventless, M silicone tackifying resins can be prepared, as describedin U.S. Pat. Nos. 5,319,040 (Wengrovius et al.), 5,302,685 (Tsumura etal.), and 4,935,484 (Wolfgruber et al.).

Certain MQ silicate tackifying resins can be prepared by the silicahydrosol capping process described in U.S. Pat. No. 2,676,182 (Daudt etal.) as modified according to U.S. Pat. No. 3,627,851 (Brady), and U.S.Pat. No. 3,772,247 (Flannigan). These modified processes often includelimiting the concentration of the sodium silicate solution, and/or thesilicon-to-sodium ratio in the sodium silicate, and/or the time beforecapping the neutralized sodium silicate solution to generally lowervalues than those disclosed by Daudt et al. The neutralized silicahydrosol is often stabilized with an alcohol, such as 2-propanol, andcapped with R₃SiO_(1/2) siloxane units as soon as possible after beingneutralized. The level of silicon bonded hydroxyl groups (i.e., silanol)on the MQ resin may be reduced to no greater than 1.5 weight percent, nogreater than 1.2 weight percent, no greater than 1.0 weight percent, orno greater than 0.8 weight percent based on the weight of the silicatetackifying resin. This may be accomplished, for example, by reactinghexamethyldisilazane with the silicate tackifying resin. Such a reactionmay be catalyzed, for example, with trifluoroacetic acid. Alternatively,trimethylchlorosilane or trimethylsilylacetamide may be reacted with thesilicate tackifying resin, a catalyst not being necessary in this case.

MQD silicone tackifying resins are terpolymers having R′₃SiO_(1/2) units(“M” units), SiO_(4/2) units(“Q” units), and R′₂SiO_(2/2) units (“D”units) such as are taught in U.S. Pat. No. 2,736,721 (Dexter). In MQDsilicone tackifying resins, some of the methyl R′ groups of theR′₂SiO_(2/2) units (“D” units) can be replaced with vinyl (CH₂═CH—)groups (“D^(Vi)” units).

MQT silicate tackifying resins are terpolymers having R′₃SiO_(1/2)units, SiO_(4/2) units and R′SiO_(3/2) units (“T” units) such as aretaught in U.S. Pat. No. 5,110,890 (Butler) and Japanese Kokai HE2-36234.

Suitable silicate tackifying resins are commercially available fromsources such as Dow Corning, Midland, Mich., General Electric SiliconesWaterford, N.Y. and Rhodia Silicones, Rock Hill, S.C. Examples ofparticularly useful MQ silicate tackifying resins include thoseavailable under the trade designations SR-545 and SR-1000, both of whichare commercially available from GE Silicones, Waterford, N.Y. Suchresins are generally supplied in organic solvent and may be employed inthe formulations of the adhesives of the present invention as received.Blends of two or more silicate resins can be included in the adhesivecompositions.

The adhesive compositions typically contain 20 to 80 weight percentpolydiorganosiloxane polyoxamide and 20 to 80 weight percent silicatetackifying resin based on the combined weight of polydiorganosiloxanepolyoxamide and silicate tackifying resin. For example, the adhesivecompositions can contain 30 to 70 weight percent polydiorganosiloxanepolyoxamide and 30 to 70 weight percent silicate tackifying resin, 35 to65 weight percent polydiorganosiloxane polyoxamide and 35 to 65 weightpercent silicate tackifying resin, 40 to 60 weight percentpolydiorganosiloxane polyoxamide and 40 to 60 weight percent silicatetackifying resin, or 45 to 55 weight percent polydiorganosiloxanepolyoxamide and 45 to 55 weight percent silicate tackifying resin.

The adhesive composition can be solvent-free or can contain a solvent.Suitable solvents include, but are not limited to, toluene,tetrahydrofuran, dichloromethane, aliphatic hydrocarbons (e.g., alkanessuch as hexane), or mixtures thereof.

Polydiorganosiloxane polyamides with a small amount of branching can besoluble in many common organic solvents such as, for example, toluene,tetrahydrofuran, dichloromethane, aliphatic hydrocarbons (e.g., alkanessuch as hexane), or mixtures thereof. Polydiorganosiloxane polyamideswith higher amounts of branching can be swellable in many common organicsolvents such as, for example, toluene, tetrahydrofuran,dichloromethane, aliphatic hydrocarbons (e.g., alkanes such as hexane),or mixtures thereof.

The polydiorganosiloxane polyamides can be cast from solvents as film,molded or embossed in various shapes, or extruded into films. The hightemperature stability of the copolymeric material makes them well suitedfor extrusion methods of film formation. The films can be opticallyclear. A multilayer film containing the polydiorganosiloxane polyamideblock copolymers is further described in U.S. patent application Ser.No. 11/614,169, filed 21 Dec. 2006.

Processes of Making Compositions and Constructions

The compositions and constructions disclosed herein can be made bysolvent-based processes known to the art, by a solventless process, orby a combination of the two.

For embodiments in which the composition or construction includes, forexample, an organic polymer, one skilled in the art can expect theoptimum material for a particular application to be a function of thearchitecture and ratios of the polydiorganosiloxane polyamide-containingcomponent, the architecture and ratios of organic polymer, optionalinitiator architecture, and whether any fillers, additives, or propertymodifiers are added.

For embodiments in which the composition or construction includes anorganic polymer, the organic polymer is generally added as a moltenstream to the polydiorganosiloxane polyamide-containing component or toone of the reactants of the polydiorganosiloxane polyamide-containingcomponent. Sometimes the polymeric material needs to be melted in aseparate vessel before the polydiorganosiloxane polyamide-containingcomponent is added (1) as pellets, (2) as reactants or (3) as a separatemolten stream from a second vessel. Examples when a separate vessel ispreferred include, for example, when (1) additives are preferred toconcentrate in the organic polymer, (2) organic polymers need highprocessing temperatures and (3) organic polymers include elastomericthermoset materials.

The order of adding the various components is important in forming themixture. For embodiments in which the composition or constructionincludes an organic polymer, any order of addition can be used if theorganic polymer is substantially unreactive with the reactants formaking the polydiorganosiloxane polyamide (e.g., diamines) as discussedearlier. The polydiorganosiloxane polyamide-containing component can beadded to the organic polymer, and vice versa, or thepolydiorganosiloxane polyamide-containing component can be made in thepresence of the organic polymer. However, the organic polymer must beadded after the polydiorganosiloxane polyamide-containing component isformed if the organic polymer is reactive with the reactants for makingsuch component. Also, the organic polymer is preferably sufficientlyheated to a processable state in a separate vessel and added to a moltenstream of the polydiorganosiloxane polyamide-containing component if thetemperature needed to process the organic polymer would degrade thepolydiorganosiloxane polyamide-containing component.

Other additives such as plasticizing materials, tackifying materials,pigments, fillers, initiators, and the like can generally be added atany point in the process since they are usually not reactive with thereactants but are typically added after a substantial amount of thepolydiorganosiloxane polyamide-containing component is formed.

For embodiments in which the composition or construction includes anorganic polymer, organic polymers that are non-thermoplastic elastomericmaterials generally need special conditions to be melt processed whenmixed with polydiorganosiloxane polyamide-containing components. Twomethods of making non-thermoplastic elastomeric materials meltprocessable are (1) reducing their apparent melt viscosity by swellingthem with tackifying or plasticizing material or (2) masticating thematerials as described in U.S. Pat. No. 5,539,033.

Four process considerations can affect the final properties of themixtures made by the solventless process. First, the properties ofpolydiorganosiloxane polyamide-containing component could be affected bywhether the polydiorganosiloxane polyamide-containing component is madein a solvent or an essentially solventless process. Secondly, thepolydiorganosiloxane polyamide-containing component can degrade ifexposed to too much heat and shear. Thirdly, the stability of themixture is affected by how the polydiorganosiloxane polyamide-containingcomponent is mixed with the organic polymer. Fourthly, the morphology ofthe article made with the mixture is determined by the interaction ofthe processing parameters and characteristics of the components in themixture.

In a first consideration, the polydiorganosiloxane polyamide-containingcomponent can be made previously by either a solvent or solventlessprocess or can be made in the presence of the organic polymer. Methodsof making the polydiorganosiloxane polyamide-containing component insolvent were disclosed above. Methods of making the polydiorganosiloxanepolyamide-containing component in substantially solventless conditionscan result in polydiorganosiloxane polyamide-containing component highin molecular weight

In a second consideration, the polydiorganosiloxane polyamide-containingcomponent can degrade if it is heated too much under shear conditions,particularly in the presence of oxygen. The polydiorganosiloxanepolyamide-containing component is exposed to the least amount of heatand shear when made in the presence of the organic polymer, and inparticular, when the mixture is made under an inert atmosphere.

In a third consideration, the stability of the mixture is affected byhow the polydiorganosiloxane polyamide-containing component is mixedwith the organic polymer. Polydiorganosiloxanes are generally immisciblewith most other polymeric materials. However, the inventors have foundthat a wide variety of polymers can be mixed with a polydiorganosiloxanepolyamide-containing component when both are in the molten state. Caremust be taken that the conditions needed to soften one component doesnot degrade the other. Preferably, the mixing temperature should be at atemperature above the mixing and conveying temperature of the mixtureand below the degradation temperature of the polydiorganosiloxanepolyamide-containing component. The polydiorganosiloxane polyoxamidecopolymer can usually be subjected to elevated temperatures up to 250°C. or higher without apparent degradation.

Any vessel in which the components can be adequately heated and mixed inthe molten state is suitable for making mixtures as disclosed herein.

In a fourth consideration, the processing steps influence the morphologyof an article made with the mixtures as disclosed herein. The mixturesgenerally have at least two domains, one discontinuous and the othercontinuous, because of the general immiscibility of thepolydiorganosiloxane polyamide-containing component with the organicpolymer. The component comprising the minor phase typically formsdiscontinuous domains that range in shape from spheroidal to ellipsoidalto ribbon-like to fibrous. The component comprising the major phasetypically forms the continuous domain that surrounds the discontinuousdomains. The discontinuous domains of the mixture generally elongate ifthe mixture is subjected to sufficient shear or extensional forces asthe mixture is formed into an article, such as a film or coating. Thediscontinuous domains generally remain elongated if at least one of thecomponents has a sufficient viscosity at use temperature to prevent theelongated domain from relaxing into a sphere when the mixture is nolonger under extensional or shear forces. The elongated morphology isusually stable until the mixture is reheated above the softening pointof the components.

While both a solvent based process and a solventless process for makingthe mixtures as disclosed herein can be used, there may be somesituations where a combination of the two is preferred. In the lattercase, a polydiorganosiloxane polyamide-containing component could bemade by the solvent based process and subsequently dried and melt mixedwith the organic polymer.

Types of Articles

Polymers and compositions of the present invention, depending onspecific formulation, can be used to make a variety of articles that canbe used, for example, as release films, optical films, diffuse opticalarticles, process aids, optical PSAs, pressure-sensitive adhesive tapes,pressure-sensitive adhesive transfer tapes, pressure-sensitive adhesivemedical tapes, including for example transdermal drug deliveringdevices, rubber-toughened articles, and pressure-sensitive adhesivecoatings directly onto desired articles.

Polymers and compositions as disclosed herein can be cast from solventsas film, molded or embossed in various shapes, or extruded into films.They can be formed into various articles, for example, one that includesa layer containing the polymer or composition and one or more optionalsubstrates. For example, the polymer or composition can be in a layeradjacent to a first substrate or positioned between a first substrateand a second substrate. That is, the article can be arranged in thefollowing order: a first substrate, a layer containing the polymer orcomposition, and a second substrate. As used herein, the term “adjacent”refers to a first layer that contacts a second layer or that ispositioned in proximity to the second layer but separated from thesecond layer by one or more additional layers.

Pressure-sensitive adhesive articles are made by applying thepressure-sensitive adhesive by well known hot melt or solvent coatingprocess. Any suitable substrates that can by used, including, but notlimited to, for example, cloth and fiber-glass cloth, metallized filmsand foils, polymeric films, nonwovens, paper and polymer coated paper,and foam backings. Polymer films include, but are not limited by,polyolefins such as polypropylene, polyethylene, low densitypolyethylene, linear low density polyethylene and high densitypolyethylene; polyesters such as polyethylene terephthalate;polycarbonates; cellulose acetates; polyimides such as that availableunder the trade designation KAPTON. Nonwovens, generally made fromrandomly oriented fibers, include, but are not limited by, nylon,polypropylene, ethylene-vinyl acetate copolymer, polyurethane, rayon andthe like. Foam backings include, but are not limited by acrylic,silicone, polyurethane, polyethylene, neoprene rubber, andpolypropylene, and may be filled or unfilled. Backings that are layered,such as polyethylene-aluminum membrane composites, are also suitable.

In the case of pressure-sensitive tapes, these materials are typicallyapplied by first making a tape construction which comprises a layer ofthe pressure-sensitive adhesive material coated on a backing. Theexposed surface of the pressure-sensitive adhesive coating may besubsequently applied to a surface from which it could be released lateror directly to the desired substrate.

Some pressure-sensitive adhesive articles use release liners, i.e.,transfer tapes that can be made by coating the composition between twoliners both of which are coated with a release coating. The releaseliners typically comprise polymeric material such as polyester,polyethylene, polyolefin and the like, or release coated paper orpolyethylene coated paper. Preferably, each release liner is firstcoated or primed with a release material for the adhesive materialsutilized in the invention. When the composition contains a significantamount of a tackified polydiorganosiloxane polyamide-containingcomponent, useful release liners include those that are suitable for usewith silicone adhesives. One example is the polyfluoropolyether coatedliner described in European Patent Publication No. 433070. Other usefulrelease liner release coating compositions are described in EuropeanPatent Publication No. 378420, U.S. Pat. No. 4,889,753, and EuropeanPatent Publication No. 311262. Commercially available liners andcompositions include that available under the trade designation SYL-OFFQ2-7785 fluorosilicone release coating from Dow Corning Corp., Midland,Mich., X-70-029NS fluorosilicone release coatings available fromShin-Etsu Silicones of America, Inc., Torrance, Calif.; that availableunder the trade designation S TAKE-OFF 2402 fluorosilicone release linerfrom Release International, Bedford Park, Ill.; and the like.

Compositions of the present invention are also useful in medicalapplications including transdermal drug delivery devices. Transdermaldrug delivery devices are designed to deliver a therapeuticallyeffective amount of drug through or to the skin of a patient.Transdermal drug delivery provides significant advantages; unlikeinjection, it is noninvasive; unlike oral administration, it avoidshepatic first pass metabolism, it minimizes gastrointestinal effects,and it provides stable blood levels.

Compositions of the present invention may also be used inpressure-sensitive adhesives that readily attach to prepared andunprepared surfaces, especially metals, polyolefin and fluorinecontaining polymeric films, providing a highly conformable, continuousinterfacial silicone coating that prevents ingress of environmentalcontaminants including those that corrosively attack unprotectedsurfaces. A pressure sensitive adhesive patch typically consists of aprotective polydiorganosiloxane polyamide-containing pressure sensitiveadhesive composition and optionally a barrier or edge adhesive, layersof conformable barrier or backing materials, or combinations of thesematerials. For some applications it is preferable that the backing doesnot shield electric field lines, making an open structure backing morepreferable to solid films of, for example, polyethylene or PVC. Atapered or profiled adhesive layer to better match surface topology maybe preferred when patching some surfaces.

Compositions of the present invention may also be used aspressure-sensitive adhesives or hot melt adhesives for heat shrinktubes. These constructions provide a single article that can withstandthe high temperatures experienced during the heat shrink operation andprovide an environmental seal after cooling. The rheology, heatstability, tack, and clarity of these materials make them especiallysuitable for this application.

Compositions of the invention can also be coated onto a differentialrelease liner; i.e., a release liner having a first release coating onone side of the liner and a second release coating coated on theopposite side. The two release coatings preferably have differentrelease values. For example, one release coating may have a releasevalue of 5 grams/cm (that is, 5 grams of force is needed to remove astrip of material 1 cm wide from the coating) while the second releasecoating may have a release value of 15 grams/cm. The material can becoated over the release liner coating having the higher release value.The resulting tape can be wound into a roll. As the tape is unwound, thepressure-sensitive adhesive adheres to the release coating with thehigher release value. After the tape is applied to a substrate, therelease liner can be removed to expose an adhesive surface for furtheruse.

Hot melt adhesives are compositions that can be used to bond nonadheringsurfaces together into a composite. During application to a substrate,hot melt adhesives should be sufficiently fluid to wet the surfacecompletely and leave no voids, even if the surface is rough.Consequently, the adhesive must be low in viscosity at the time ofapplication. However, the bonding adhesive generally sets into a solidto develop sufficient cohesive strength to remain adhered to thesubstrate under stressful conditions.

For hot melt adhesives, the transition from fluid to solid may beaccomplished in several ways. First, the hot melt adhesive may be athermoplastic that softens and melts when heated and becomes hard againwhen cooled. Such heating results in sufficiently high fluidity toachieve successful wetting. Alternatively, the hot melt adhesive may bedissolved in a solvent or carrier that lowers the viscosity of theadhesive sufficiently to permit satisfactory wetting and raises theadhesive viscosity when the solvent or carrier is removed. Such anadhesive can be heat activated, if necessary.

Compositions of the present invention can be formed into unsupportedfilms, which can be used, for example, as release articles, adhesivetransfer tapes, optical adhesives, hot melt adhesives, optical articles,diffusers, non-woven webs, water repellant films, rubber toughenedplastics, anti-graffiti films, casting liners, pressure sensitiveadhesives, vibration dampers, acoustic dampers, medical backings, tapebackings, medical articles, and sealants.

Compositions of the present invention can be incorporated into one ormore layers of a multilayer film, which can be used, for example, forthe uses described herein above for unsupported films. In addition, themultilayer films can be used, for example, as relective polarizers,infra-red radiation reflectors, diffusers, optical filters, pressuresensitive adhesives, vibration dampers, acoustic dampers, reflectors,and permeable films.

Compositions of the present invention can be used in melt process aids,which can be used, for example, for surface modification, slip aids,compatibiliziers, refractive index modifiers, impact modifiers, opticsmodifiers, rheology modifiers, permeability modification, waterrepellency, fiber treatment to impart a perfect smoothness, lubricity,reduced tackiness, and pleasant tactile sensations.

The following exemplary embodiments are provided by the presentdisclosure:

Embodiment 1. A copolymer comprising at least two repeat units ofFormula I-a:

each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, oraryl substituted with an alkyl, alkoxy, or halo; G is a polyvalentresidue having a valence of q; R³ is hydrogen or alkyl or R³ takentogether with G and to the nitrogen to which they are both attached forma heterocyclic group; each Y is independently an alkylene, aralkylene,or a combination thereof; each B is independently a covalent bond, analkylene of 4-20 carbons, an aralkylene, an arylene, or a combinationthereof; n is independently an integer of 0 to 1500; p is an integer ofIto 10; and q is an integer greater than 2.

Embodiment 2. The copolymer of embodiment 1, wherein the copolymercomprises at least two repeat units of Formula I-b:

Embodiment 3. The copolymer of embodiment 1 or 2 wherein q is an integergreater than or equal to 3.

Embodiment 4. The copolymer of any of embodiments 1 to 3 wherein q is aninteger greater than or equal to 4.

Embodiment 5. The copolymer of any of embodiments 1 to 3 wherein q isequal to 3.

Embodiment 6. The copolymer of any of embodiments 1 to 5, wherein eachR¹ is methyl.

Embodiment 7. The copolymer of any of embodiments 1 to 5, wherein atleast 50 percent of the R¹ groups are methyl.

Embodiment 8. The copolymer of any of embodiments 1 to 7, wherein each Yis an alkylene having 1 to 10 carbon atoms, phenylene bonded to analkylene having 1 to 10 carbon atoms, or phenylene bonded to a firstalkylene having 1 to 10 carbon atoms and to a second alkylene having 1to 10 carbon atoms.

Embodiment 9. The copolymer of any of embodiments 1 to 8, wherein Y isan alkylene having 1 to 4 carbon atoms.

Embodiment 10. The copolymer of any of embodiments 1 to 9, wherein thecopolymer has a first repeat unit where p is equal to 1 and a secondrepeat unit where p is at least 2.

Embodiment 11. The copolymer of any of embodiments 1 to 10, wherein n isat least 40.

Embodiment 12. The copolymer of any of embodiments 1 to 11, wherein R³is hydrogen.

Embodiment 13. The copolymer of any of embodiments 1 to 12 furthercomprising one or more repeat units different than the at least tworepeat units of Formula I-a.

Embodiment 14. The copolymer of embodiment 13 wherein the differentrepeat units are of Formula I-a, except that q is equal to 2.

Embodiment 15. A method of making a copolymer having at least two repeatunits of Formula I-a, the method comprising mixing together underreaction conditions: a) a precursor of Formula II-a:

and b) one or more amine compounds having on average a formulaG(NHR³)_(r), wherein: each R¹ is independently an alkyl, haloalkyl,aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, orhalo; each R² is independently an alkyl, haloalkyl, aryl, or arylsubstituted with an alkyl, alkoxy, halo, or alkoxycarbonyl; G is apolyvalent residue unit equal to the formula G(NHR³)_(r) minus the r—NHR³ groups; R³ is hydrogen or alkyl or R³ taken together with G andwith the nitrogen to which they are both attached forms a heterocyclicgroup; and each Y is independently an alkylene, aralkylene, or acombination thereof; each B is independently a covalent bond, analkylene of 4-20 carbons, an aralkylene, an arylene, or a combinationthereof; and n is independently an integer of 0 to 1500; p is an integerof 1 to 10; and r is a number greater than 2.

Embodiment 16. The method of embodiment 15 wherein the one or more aminecompounds include a diamine.

Embodiment 17. The method of embodiment 15 or 16, where R³ is hydrogen.

Embodiment 18. The method of any of embodiments 15 to 17, wherein themethod further comprises removing a reaction by-product of formula R²OHfrom the copolymer.

Embodiment 19. The method of any of embodiments 15 to 18, wherein R¹ ismethyl and R³ is hydrogen.

Embodiment 20. The method of any of embodiments 15 to 19, wherein themixing of the precursor and the one or more amine compounds is a batchprocess, a semi-batch process, or a continuous process.

Embodiment 21. A method of making a copolymer having at least two repeatunits of Formula I-b, the method comprising mixing together underreaction conditions: a) a precursor of Formula II-b:

and b) one or more amine compounds having on average a formulaG(NHR³)_(r), wherein each R¹ is independently an alkyl, haloalkyl,aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, orhalo; each R² is independently an alkyl, haloalkyl, aryl, or arylsubstituted with an alkyl, alkoxy, halo, or alkoxycarbonyl; G is apolyvalent residue unit equal to the formula G(NHR³)_(r) minus the r—NHR³ groups; R³ is hydrogen or alkyl or R³ taken together with G andwith the nitrogen to which they are both attached forms a heterocyclicgroup; each Y is independently an alkylene, aralkylene, or a combinationthereof; n is independently an integer of 0 to 1500; p is an integer of1 to 10; and r is a number greater than 2.

Embodiment 22. The method of embodiment 21, wherein the precursor ofFormula II-b is prepared by reacting a polydiorganosiloxane diamine ofFormula III

with a molar excess of an oxalate of Formula IV

wherein R² is an alkyl, haloalkyl, aryl, or aryl substituted with analkyl, alkoxy, halo, or alkoxycarbonyl.

Embodiment 23. The method of embodiment 22, wherein the excess oxalateis removed after reaction with the polydiorganosiloxane diamine.

Embodiment 24. An article comprising a copolymer according to any ofembodiments 1 to 14.

Embodiment 25. The article of embodiment 24 further comprising asubstrate, wherein the copolymer is in a layer adjacent to thesubstrate.

Embodiment 26. The article of embodiment 24 further comprising a firstsubstrate and a second substrate, wherein the copolymer is in a layerpositioned between the first substrate and the second substrate.

Embodiment 27. A composition comprising a copolymer according to any ofembodiments 1 to 14.

Embodiment 28. The composition of embodiment 27 further comprising apolymeric material different than the copolymer.

Embodiment 29. The composition of embodiment 28 wherein the polymericmaterial different than the copolymer comprises at least 2 repeat unitsof Formula V-a:

wherein: each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl,aryl, or aryl substituted with an alkyl, alkoxy, or halo; G is adivalent residue equal to a diamine of formula R³HN-G-NHR³ minus the two—NHR³ groups; R³ is hydrogen, alkyl, or taken together with G and to thenitrogen to which they are both attached form a heterocyclic group; eachY is independently an alkylene, aralkylene, or a combination thereof;each B is independently a covalent bond, an alkylene of 4-20 carbons, anaralkylene, an arylene, or a combination thereof; n is independently aninteger of 0 to 1500; and p is an integer of 1 to 10.

Embodiment 30. The composition of embodiment 28 or 29 wherein thepolymeric material different than the copolymer comprises at least tworepeat units of Formula V-b:

each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, oraryl substituted with an alkyl, alkoxy, or halo; G is a divalent residueequal to a diamine of formula R³HN-G-NHR³ minus the two —NHR³ groups; R³is hydrogen or alkyl or R³ taken together with G and to the nitrogen towhich they are both attached form a heterocyclic group; each Y isindependently an alkylene, aralkylene, or a combination thereof; n isindependently an integer of 0 to 1500; and p is an integer of 1 to 10.

Embodiment 31. The composition of any of embodiments 28 to 30 furthercomprising a tackifying material.

Embodiment 32. The composition of embodiment 31 wherein the tackifyingmaterial is a silicate resin or an organic tackifier.

Embodiment 33. The composition of any of embodiments 27 to 32 whereinthe composition is an adhesive.

Embodiment 34. The composition of any of embodiments 27 to 33 furthercomprising one or more additives.

Embodiment 35. A composite film comprising: a first film comprising alight transmissive material; and a second film contiguous to said firstfilm, the second film comprising a copolymer according to any ofembodiments 1 to 14.

Embodiment 36. A film comprising: a first layer comprising a firstpolymeric material having a first index of refraction; and a secondlayer contiguous to the first layer, the second layer having a secondindex of refraction and comprising a copolymer according to any ofembodiments 1 to 14.

Embodiment 37. The film of embodiment 36 further comprising a thirdlayer contiguous with either the first layer or the second layer, thethird layer comprising a third material.

Embodiment 38. The film of embodiment 37 wherein the third layer isdisposed between the first layer and the second layer.

The foregoing describes the invention in terms of embodiments foreseenby the inventor for which an enabling description was available,notwithstanding that insubstantial modifications of the invention, notpresently foreseen, may nonetheless represent equivalents thereto.

EXAMPLES

These examples are merely for illustrative purposes only and are notmeant to be limiting on the scope of the appended claims. All parts,percentages, ratios, and the like in the examples are by weight, unlessnoted otherwise. Solvents and other reagents used were obtained fromSigma-Aldrich Chemical Company; Milwaukee, Wis. unless otherwise noted.

Table of Abbreviations Abbreviation or Trade Designation Description 5KPDMS A polydimethylsiloxane diamine with diamine an average molecularweight of 5,000 g/mole that was prepared as described in U.S. Pat. No.5,214,119 (Leir et al.). 14K PDMS Polydimethylsiloxane diamine withdiamine an approximate molecular weight of 14,000 g/mole that wasprepared as described in U.S. Pat. No. 6,355,759 (Sherman et al.). TolToluene THF Tetrahydrofuran EDA Ethylene diamine TF Tri functionalamine- Tris(2-aminoethyl)amineInherent Viscosity (IV) for Polydiorganosiloxane Polyoxamide BlockCopolymer

Average inherent viscosities (IV) were measured at 30° C. using aCanon-Fenske viscometer (Model No. 50 P296) in a tetrahydrofuran (THF)solution at 30° C. at a concentration of 0.2 g/dL. Inherent viscositiesof the materials of the invention were found to be essentiallyindependent of concentration in the range of 0.1 to 0.4 g/dL. Theaverage inherent viscosities were averaged over 3 or more runs. Anyvariations for determining average inherent viscosities are set forth inspecific Examples.

Titration Method to Determine Equivalent Weight

Approximately 10 grams (precisely weighed) of the precursor compoundfrom the reaction of the PDMS Diamine and the diethyl oxalate was addedto a jar. Approximately 50 grams THF solvent (not precisely weighed) wasadded. The contents were mixed using a magnetic stir bar mix until themixture was homogeneous. The theoretical equivalent weight of precursorwas calculated and then an amount of N-hexylamine (precisely weighed) inthe range of 3 to 4 times this number of equivalents was added. Thereaction mixture was stirred for a minimum of 4 hours. Bromophenol blue(10-20 drops) was added and the contents were mixed until homogeneous.The mixture was titrated to a yellow endpoint with 1.0N (or 0.1N)hydrochloric acid. The number of equivalents of precursor was equal tothe number of equivalents of N-hexylamine added to the sample minus thenumber of equivalents of hydrochloric acid added during titration. Theequivalent weight (grams/equivalent) was equal to the sample weight ofthe precursor divided by the number of equivalents of the precursor.

Preparative Example 1

Diethyl oxalate (241.10 grams) was placed in a 3 liter, 3-neck resinflask equipped with a mechanical stirrer, heating mantle, nitrogen inlettube (with stopcock), and an outlet tube. The flask was purged withnitrogen for 15 minutes and 5 k PDMS diamine (a polydimethylsiloxanediamine with an average molecular weight of 5,000 g/mole that wasprepared as described in U.S. Pat. No. 5,214,119 (Leir et al.))(2,028.40 grams, MW=4,918) was added slowly with stirring. After 8 hoursat room temperature, the reaction flask was fitted with a distillationadaptor and receiver, the contents stirred and heated to 150° C. undervacuum (1 Torr) for 4 hours, until no further distillate was able to becollected. The remaining liquid was cooled to room temperature toprovide 2,573 grams of oxamido ester terminated product. Gaschromatographic analysis of the clear, mobile liquid showed that nodetectable level of diethyl oxalate remained. Molecular weight wasdetermined by ¹H NMR (MW=5,477 grams/mole) and titration (Equivalentweights of 2,573 grams/mole and 2,578 grams/mole).

Preparative Example 2

A sample of 14K PDMS diamine (830.00 grams) was placed in a 2 liter,3-neck resin flask equipped with a mechanical stirrer, heating mantle,nitrogen inlet tube (with stopcock), and an outlet tube. The flask waspurged with nitrogen for 15 minutes and then, with vigorous stirring,diethyl oxalate (33.56 grams) was added dropwise. This reaction mixturewas stirred for approximately one hour at room temperature and then for75 minutes at 80° C. The reaction flask was fitted with a distillationadaptor and receiver. The reaction mixture was heated under vacuum (133Pascals, 1 Torr) for 2 hours at 120° C. and then 30 minutes at 130° C.,until no further distillate was able to be collected. The reactionmixture was cooled to room temperature to provide the compound ofFormula I product. Gas chromatographic analysis of the clear, mobileliquid showed that no detectable level of diethyl oxalate remained. Theester equivalent weight was determined using ¹H NMR (equivalent weightequal to 7,916 grams/equivalent) and by titration (equivalent weightequal to 8,272 grams/equivalent).

Example 1

Into a 20° C. 10 gallon stainless steel reaction vessel, 40 pounds ofPreparative Example 1 was placed. The vessel was subjected to agitation(80 rpm) and purged with nitrogen flow and vacuum for 15 minutes. Thereactor was the nitrogen pressurized to 5 pounds per square inch andheated to 90° C. over the course of 25 minutes. 0.44 pounds of ethylenediamine was added to the reactor. This addition was followed by 80 gramsof toluene. Next the reactor was heated to a temperature of 105° C. andthe pressure on the reactor was slowly vented over the course for 5minute. The reactor was then subjected to vacuum (approximately 20 mmHg)for one hour to remove the ethanol and toluene. The reactor was thenrepressurized to 2 psig and the viscous molten product was drained intoa Teflon coated tray and allowed to cool. The cooled siliconepolyoxamide product, was then ground into fine pellets. The IV of thismaterial was determined to be 1.135 g/dL (in THF).

Example 2

This example was prepared as in Example 1 except that 0.5 mole % of theethylene diamine (EDA) was replaced with an equal number of moles ofTris(2-aminoethyl)amine (TF amine). The IV of this material wasdetermined to be 1.274 g/dL (in THF).

Example 3

This example was prepared as in Example 1 except that 1.0 mole % of theethylene diamine (EDA) was replaced with an equal number of moles ofTris(2-aminoethyl)amine (TF amine). The IV of this material wasdetermined to be 1.37 g/dL (in THF).

Example 4

This example was prepared as in Example 1 except that 2.0 mole % of theethylene diamine (EDA) was replaced with an equal number of moles ofTris(2-aminoethyl)amine (TF amine). The IV of this material wasdetermined to be 1.43 g/dL (in THF).

Example 5

Into a 20° C. 10 gallon stainless steel reaction vessel, 18158.4 gramsof the precursor of Preparative Example 2, ethyl oxalylamidopropylterminated 14 k PDMS diamine (titrated MW=14,890), was placed. Thevessel was subjected to agitation (75 rpm), and purged with nitrogenflow and vacuum for 15 minutes. The kettle was then heated to 80° C.over the course of 25 minutes. 73.29 grams of ethylene diamine (GFSChemicals) were vacuum charged into the kettle, followed by 73.29 gramsof toluene (also vacuum charged). The kettle was then pressurized to 1psig and heated to a temperature of 120° C. After 30 minutes, the kettlewas heated to 150° C. Once a temperature of 150° C. was reached, thekettle was vented over the course of 5 minutes. The kettle was subjectedto vacuum (approximately 65 mmHg) for 40 minutes to remove the ethanoland toluene. The kettle was then pressured to 2 psig and the viscousmolten polymer was then drained into Teflon coated trays and allowed tocool. The cooled silicone polyoxamide product, polydiorganosiloxanepolyoxamide block copolymer, was then ground into fine pellets. The IVof this material was determined to be 0.829 g/dL (in THF).

Example 6

This example was prepared as in Example 5 except that 1.0 mole % of theethylene diamine (EDA) was replaced with an equal number of moles ofTris(2-aminoethyl)amine (TF amine). The IV of this material wasdetermined to be 1.062 g/dL (in THF).

Example 7

This example was prepared as in Example 5 except that 2.0 mole % of theethylene diamine (EDA) was replaced with an equal number of moles ofTris(2-aminoethyl)amine (TF amine). The IV of this material wasdetermined to be 1.194 g/dL (in THF).

The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as follows.

1. An article comprising a release layer, the release layer comprising:a copolymer comprising at least two repeat units of Formula I-a:

each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, oraryl substituted with an alkyl, alkoxy, or halo; G is a polyvalentresidue having a valence of q; R³ is hydrogen or alkyl or R³ takentogether with G and to the nitrogen to which they are both attached forma heterocyclic group; each Y is independently an alkylene, aralkylene,or a combination thereof; each B is independently an alkylene of 4-20carbons, an aralkylene, an arylene, or a combination thereof; n isindependently an integer of 0 to 1500; p is an integer of 1 to 10; and qis an integer greater than
 2. 2. The article of claim 1, wherein thecopolymer comprises at least two repeat units of Formula I-b:

each R¹ is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, oraryl substituted with an alkyl, alkoxy, or halo; G is a polyvalentresidue having a valence of q; R³ is hydrogen or alkyl or R³ takentogether with G and to the nitrogen to which they are both attached forma heterocyclic group; each Y is independently an alkylene, aralkylene,or a combination thereof; n is independently an integer of 0 to 1500; pis an integer of 1 to 10; and q is an integer greater than 2; and anadditive, wherein the additive comprises a polymer, a functionalcomponent, a property modifier or combinations thereof.
 3. A pressuresensitive adhesive article comprising an adhesive layer, and a releaselayer of claim 2 on the adhesive layer.
 4. The article of claim 2,comprising a functional component, wherein the functional componentcomprises an antistatic additive, a nanoparticle, an electricalconductor, a metal particle or combinations thereof.
 5. The article ofclaim 2, comprising a functional component, wherein the functionalcomponent comprises fumed silica, glass beads, glass bubbles, glassfibers, mineral fibers, clay particles, organic fibers or combinationsthereof.
 6. The article of claim 2, comprising a functional component,wherein the functional component comprises antimicrobial agents.
 7. Apressure sensitive adhesive article comprising an adhesive layer, and arelease layer of claim 1 on the adhesive layer.
 8. The article of claim1, comprising a functional component, wherein the functional componentcomprises an antistatic additive, a nanoparticle, an electricalconductor, a metal particle or combinations thereof.
 9. The article ofclaim 1, comprising a functional component, wherein the functionalcomponent comprises fumed silica, glass beads, glass bubbles, glassfibers, mineral fibers, clay particles, organic fibers or combinationsthereof.
 10. The article of claim 1, comprising a functional component,wherein the functional component comprises antimicrobial agents.